// <mutex> -*- C++ -*-// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010// Free Software Foundation, Inc.//// This file is part of the GNU ISO C++ Library. This library is free// software; you can redistribute it and/or modify it under the// terms of the GNU General Public License as published by the// Free Software Foundation; either version 3, or (at your option)// any later version.// This library is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the// GNU General Public License for more details.// Under Section 7 of GPL version 3, you are granted additional// permissions described in the GCC Runtime Library Exception, version// 3.1, as published by the Free Software Foundation.// You should have received a copy of the GNU General Public License and// a copy of the GCC Runtime Library Exception along with this program;// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see// <http://www.gnu.org/licenses/>./** @file include/mutex* This is a Standard C++ Library header.*/#ifndef _GLIBCXX_MUTEX#define _GLIBCXX_MUTEX 1#pragma GCC system_header#ifndef __GXX_EXPERIMENTAL_CXX0X__# include <bits/c++0x_warning.h>#else#include <tuple>#include <chrono>#include <exception>#include <type_traits>#include <functional>#include <system_error>#include <bits/functexcept.h>#include <bits/gthr.h>#include <bits/move.h> // for std::swap#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)namespace std _GLIBCXX_VISIBILITY(default){_GLIBCXX_BEGIN_NAMESPACE_VERSION/*** @defgroup mutexes Mutexes* @ingroup concurrency** Classes for mutex support.* @{*//// mutexclass mutex{typedef __gthread_mutex_t __native_type;__native_type _M_mutex;public:typedef __native_type* native_handle_type;#ifdef __GTHREAD_MUTEX_INITconstexpr mutex() : _M_mutex(__GTHREAD_MUTEX_INIT) { }#elsemutex(){// XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)__GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);}~mutex() { __gthread_mutex_destroy(&_M_mutex); }#endifmutex(const mutex&) = delete;mutex& operator=(const mutex&) = delete;voidlock(){int __e = __gthread_mutex_lock(&_M_mutex);// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)if (__e)__throw_system_error(__e);}booltry_lock(){// XXX EINVAL, EAGAIN, EBUSYreturn !__gthread_mutex_trylock(&_M_mutex);}voidunlock(){// XXX EINVAL, EAGAIN, EPERM__gthread_mutex_unlock(&_M_mutex);}native_handle_typenative_handle(){ return &_M_mutex; }};#ifndef __GTHREAD_RECURSIVE_MUTEX_INIT// FIXME: gthreads doesn't define __gthread_recursive_mutex_destroy// so we need to obtain a __gthread_mutex_t to destroyclass __destroy_recursive_mutex{template<typename _Mx, typename _Rm>static void_S_destroy_win32(_Mx* __mx, _Rm const* __rmx){__mx->counter = __rmx->counter;__mx->sema = __rmx->sema;__gthread_mutex_destroy(__mx);}public:// matches a gthr-win32.h recursive mutextemplate<typename _Rm>static typename enable_if<sizeof(&_Rm::sema), void>::type_S_destroy(_Rm* __mx){__gthread_mutex_t __tmp;_S_destroy_win32(&__tmp, __mx);}// matches a recursive mutex with a member 'actual'template<typename _Rm>static typename enable_if<sizeof(&_Rm::actual), void>::type_S_destroy(_Rm* __mx){ __gthread_mutex_destroy(&__mx->actual); }// matches when there's only one mutex typetemplate<typename _Rm>statictypename enable_if<is_same<_Rm, __gthread_mutex_t>::value, void>::type_S_destroy(_Rm* __mx){ __gthread_mutex_destroy(__mx); }};#endif/// recursive_mutexclass recursive_mutex{typedef __gthread_recursive_mutex_t __native_type;__native_type _M_mutex;public:typedef __native_type* native_handle_type;#ifdef __GTHREAD_RECURSIVE_MUTEX_INITrecursive_mutex() : _M_mutex(__GTHREAD_RECURSIVE_MUTEX_INIT) { }#elserecursive_mutex(){// XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);}~recursive_mutex(){ __destroy_recursive_mutex::_S_destroy(&_M_mutex); }#endifrecursive_mutex(const recursive_mutex&) = delete;recursive_mutex& operator=(const recursive_mutex&) = delete;voidlock(){int __e = __gthread_recursive_mutex_lock(&_M_mutex);// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)if (__e)__throw_system_error(__e);}booltry_lock(){// XXX EINVAL, EAGAIN, EBUSYreturn !__gthread_recursive_mutex_trylock(&_M_mutex);}voidunlock(){// XXX EINVAL, EAGAIN, EBUSY__gthread_recursive_mutex_unlock(&_M_mutex);}native_handle_typenative_handle(){ return &_M_mutex; }};/// timed_mutexclass timed_mutex{typedef __gthread_mutex_t __native_type;#ifdef _GLIBCXX_USE_CLOCK_MONOTONICtypedef chrono::monotonic_clock __clock_t;#elsetypedef chrono::high_resolution_clock __clock_t;#endif__native_type _M_mutex;public:typedef __native_type* native_handle_type;#ifdef __GTHREAD_MUTEX_INITtimed_mutex() : _M_mutex(__GTHREAD_MUTEX_INIT) { }#elsetimed_mutex(){__GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);}~timed_mutex() { __gthread_mutex_destroy(&_M_mutex); }#endiftimed_mutex(const timed_mutex&) = delete;timed_mutex& operator=(const timed_mutex&) = delete;voidlock(){int __e = __gthread_mutex_lock(&_M_mutex);// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)if (__e)__throw_system_error(__e);}booltry_lock(){// XXX EINVAL, EAGAIN, EBUSYreturn !__gthread_mutex_trylock(&_M_mutex);}template <class _Rep, class _Period>booltry_lock_for(const chrono::duration<_Rep, _Period>& __rtime){ return __try_lock_for_impl(__rtime); }template <class _Clock, class _Duration>booltry_lock_until(const chrono::time_point<_Clock, _Duration>& __atime){chrono::time_point<_Clock, chrono::seconds> __s =chrono::time_point_cast<chrono::seconds>(__atime);chrono::nanoseconds __ns =chrono::duration_cast<chrono::nanoseconds>(__atime - __s);__gthread_time_t __ts = {static_cast<std::time_t>(__s.time_since_epoch().count()),static_cast<long>(__ns.count())};return !__gthread_mutex_timedlock(&_M_mutex, &__ts);}voidunlock(){// XXX EINVAL, EAGAIN, EBUSY__gthread_mutex_unlock(&_M_mutex);}native_handle_typenative_handle(){ return &_M_mutex; }private:template<typename _Rep, typename _Period>typename enable_if<ratio_less_equal<__clock_t::period, _Period>::value, bool>::type__try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime){__clock_t::time_point __atime = __clock_t::now()+ chrono::duration_cast<__clock_t::duration>(__rtime);return try_lock_until(__atime);}template <typename _Rep, typename _Period>typename enable_if<!ratio_less_equal<__clock_t::period, _Period>::value, bool>::type__try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime){__clock_t::time_point __atime = __clock_t::now()+ ++chrono::duration_cast<__clock_t::duration>(__rtime);return try_lock_until(__atime);}};/// recursive_timed_mutexclass recursive_timed_mutex{typedef __gthread_recursive_mutex_t __native_type;#ifdef _GLIBCXX_USE_CLOCK_MONOTONICtypedef chrono::monotonic_clock __clock_t;#elsetypedef chrono::high_resolution_clock __clock_t;#endif__native_type _M_mutex;public:typedef __native_type* native_handle_type;#ifdef __GTHREAD_RECURSIVE_MUTEX_INITrecursive_timed_mutex() : _M_mutex(__GTHREAD_RECURSIVE_MUTEX_INIT) { }#elserecursive_timed_mutex(){// XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);}~recursive_timed_mutex(){ __destroy_recursive_mutex::_S_destroy(&_M_mutex); }#endifrecursive_timed_mutex(const recursive_timed_mutex&) = delete;recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;voidlock(){int __e = __gthread_recursive_mutex_lock(&_M_mutex);// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)if (__e)__throw_system_error(__e);}booltry_lock(){// XXX EINVAL, EAGAIN, EBUSYreturn !__gthread_recursive_mutex_trylock(&_M_mutex);}template <class _Rep, class _Period>booltry_lock_for(const chrono::duration<_Rep, _Period>& __rtime){ return __try_lock_for_impl(__rtime); }template <class _Clock, class _Duration>booltry_lock_until(const chrono::time_point<_Clock, _Duration>& __atime){chrono::time_point<_Clock, chrono::seconds> __s =chrono::time_point_cast<chrono::seconds>(__atime);chrono::nanoseconds __ns =chrono::duration_cast<chrono::nanoseconds>(__atime - __s);__gthread_time_t __ts = {static_cast<std::time_t>(__s.time_since_epoch().count()),static_cast<long>(__ns.count())};return !__gthread_recursive_mutex_timedlock(&_M_mutex, &__ts);}voidunlock(){// XXX EINVAL, EAGAIN, EBUSY__gthread_recursive_mutex_unlock(&_M_mutex);}native_handle_typenative_handle(){ return &_M_mutex; }private:template<typename _Rep, typename _Period>typename enable_if<ratio_less_equal<__clock_t::period, _Period>::value, bool>::type__try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime){__clock_t::time_point __atime = __clock_t::now()+ chrono::duration_cast<__clock_t::duration>(__rtime);return try_lock_until(__atime);}template <typename _Rep, typename _Period>typename enable_if<!ratio_less_equal<__clock_t::period, _Period>::value, bool>::type__try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime){__clock_t::time_point __atime = __clock_t::now()+ ++chrono::duration_cast<__clock_t::duration>(__rtime);return try_lock_until(__atime);}};/// Do not acquire ownership of the mutex.struct defer_lock_t { };/// Try to acquire ownership of the mutex without blocking.struct try_to_lock_t { };/// Assume the calling thread has already obtained mutex ownership/// and manage it.struct adopt_lock_t { };constexpr defer_lock_t defer_lock { };constexpr try_to_lock_t try_to_lock { };constexpr adopt_lock_t adopt_lock { };/// @brief Scoped lock idiom.// Acquire the mutex here with a constructor call, then release with// the destructor call in accordance with RAII style.template<typename _Mutex>class lock_guard{public:typedef _Mutex mutex_type;explicit lock_guard(mutex_type& __m) : _M_device(__m){ _M_device.lock(); }lock_guard(mutex_type& __m, adopt_lock_t) : _M_device(__m){ } // calling thread owns mutex~lock_guard(){ _M_device.unlock(); }lock_guard(const lock_guard&) = delete;lock_guard& operator=(const lock_guard&) = delete;private:mutex_type& _M_device;};/// unique_locktemplate<typename _Mutex>class unique_lock{public:typedef _Mutex mutex_type;unique_lock(): _M_device(0), _M_owns(false){ }explicit unique_lock(mutex_type& __m): _M_device(&__m), _M_owns(false){lock();_M_owns = true;}unique_lock(mutex_type& __m, defer_lock_t): _M_device(&__m), _M_owns(false){ }unique_lock(mutex_type& __m, try_to_lock_t): _M_device(&__m), _M_owns(_M_device->try_lock()){ }unique_lock(mutex_type& __m, adopt_lock_t): _M_device(&__m), _M_owns(true){// XXX calling thread owns mutex}template<typename _Clock, typename _Duration>unique_lock(mutex_type& __m,const chrono::time_point<_Clock, _Duration>& __atime): _M_device(&__m), _M_owns(_M_device->try_lock_until(__atime)){ }template<typename _Rep, typename _Period>unique_lock(mutex_type& __m,const chrono::duration<_Rep, _Period>& __rtime): _M_device(&__m), _M_owns(_M_device->try_lock_for(__rtime)){ }~unique_lock(){if (_M_owns)unlock();}unique_lock(const unique_lock&) = delete;unique_lock& operator=(const unique_lock&) = delete;unique_lock(unique_lock&& __u): _M_device(__u._M_device), _M_owns(__u._M_owns){__u._M_device = 0;__u._M_owns = false;}unique_lock& operator=(unique_lock&& __u){if(_M_owns)unlock();unique_lock(std::move(__u)).swap(*this);__u._M_device = 0;__u._M_owns = false;return *this;}voidlock(){if (!_M_device)__throw_system_error(int(errc::operation_not_permitted));else if (_M_owns)__throw_system_error(int(errc::resource_deadlock_would_occur));else{_M_device->lock();_M_owns = true;}}booltry_lock(){if (!_M_device)__throw_system_error(int(errc::operation_not_permitted));else if (_M_owns)__throw_system_error(int(errc::resource_deadlock_would_occur));else{_M_owns = _M_device->try_lock();return _M_owns;}}template<typename _Clock, typename _Duration>booltry_lock_until(const chrono::time_point<_Clock, _Duration>& __atime){if (!_M_device)__throw_system_error(int(errc::operation_not_permitted));else if (_M_owns)__throw_system_error(int(errc::resource_deadlock_would_occur));else{_M_owns = _M_device->try_lock_until(__atime);return _M_owns;}}template<typename _Rep, typename _Period>booltry_lock_for(const chrono::duration<_Rep, _Period>& __rtime){if (!_M_device)__throw_system_error(int(errc::operation_not_permitted));else if (_M_owns)__throw_system_error(int(errc::resource_deadlock_would_occur));else{_M_owns = _M_device->try_lock_for(__rtime);return _M_owns;}}voidunlock(){if (!_M_owns)__throw_system_error(int(errc::operation_not_permitted));else if (_M_device){_M_device->unlock();_M_owns = false;}}voidswap(unique_lock& __u){std::swap(_M_device, __u._M_device);std::swap(_M_owns, __u._M_owns);}mutex_type*release(){mutex_type* __ret = _M_device;_M_device = 0;_M_owns = false;return __ret;}boolowns_lock() const{ return _M_owns; }explicit operator bool() const{ return owns_lock(); }mutex_type*mutex() const{ return _M_device; }private:mutex_type* _M_device;bool _M_owns; // XXX use atomic_bool};template<typename _Mutex>inline voidswap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y){ __x.swap(__y); }template<int _Idx>struct __unlock_impl{template<typename... _Lock>static void__do_unlock(tuple<_Lock&...>& __locks){std::get<_Idx>(__locks).unlock();__unlock_impl<_Idx - 1>::__do_unlock(__locks);}};template<>struct __unlock_impl<-1>{template<typename... _Lock>static void__do_unlock(tuple<_Lock&...>&){ }};template<typename _Lock>unique_lock<_Lock>__try_to_lock(_Lock& __l){ return unique_lock<_Lock>(__l, try_to_lock); }template<int _Idx, bool _Continue = true>struct __try_lock_impl{template<typename... _Lock>static void__do_try_lock(tuple<_Lock&...>& __locks, int& __idx){__idx = _Idx;auto __lock = __try_to_lock(std::get<_Idx>(__locks));if (__lock.owns_lock()){__try_lock_impl<_Idx + 1, _Idx + 2 < sizeof...(_Lock)>::__do_try_lock(__locks, __idx);if (__idx == -1)__lock.release();}}};template<int _Idx>struct __try_lock_impl<_Idx, false>{template<typename... _Lock>static void__do_try_lock(tuple<_Lock&...>& __locks, int& __idx){__idx = _Idx;auto __lock = __try_to_lock(std::get<_Idx>(__locks));if (__lock.owns_lock()){__idx = -1;__lock.release();}}};/** @brief Generic try_lock.* @param __l1 Meets Mutex requirements (try_lock() may throw).* @param __l2 Meets Mutex requirements (try_lock() may throw).* @param __l3 Meets Mutex requirements (try_lock() may throw).* @return Returns -1 if all try_lock() calls return true. Otherwise returns* a 0-based index corresponding to the argument that returned false.* @post Either all arguments are locked, or none will be.** Sequentially calls try_lock() on each argument.*/template<typename _Lock1, typename _Lock2, typename... _Lock3>inttry_lock(_Lock1& __l1, _Lock2& __l2, _Lock3&... __l3){int __idx;auto __locks = std::tie(__l1, __l2, __l3...);__try{ __try_lock_impl<0>::__do_try_lock(__locks, __idx); }__catch(...){ }return __idx;}/** @brief Generic lock.* @param __l1 Meets Mutex requirements (try_lock() may throw).* @param __l2 Meets Mutex requirements (try_lock() may throw).* @param __l3 Meets Mutex requirements (try_lock() may throw).* @throw An exception thrown by an argument's lock() or try_lock() member.* @post All arguments are locked.** All arguments are locked via a sequence of calls to lock(), try_lock()* and unlock(). If the call exits via an exception any locks that were* obtained will be released.*/template<typename _L1, typename _L2, typename ..._L3>voidlock(_L1& __l1, _L2& __l2, _L3&... __l3){while (true){unique_lock<_L1> __first(__l1);int __idx;auto __locks = std::tie(__l2, __l3...);__try_lock_impl<0, sizeof...(_L3)>::__do_try_lock(__locks, __idx);if (__idx == -1){__first.release();return;}}}/// once_flagstruct once_flag{private:typedef __gthread_once_t __native_type;__native_type _M_once;public:constexpr once_flag() : _M_once(__GTHREAD_ONCE_INIT) { }once_flag(const once_flag&) = delete;once_flag& operator=(const once_flag&) = delete;template<typename _Callable, typename... _Args>friend voidcall_once(once_flag& __once, _Callable&& __f, _Args&&... __args);};#ifdef _GLIBCXX_HAVE_TLSextern __thread void* __once_callable;extern __thread void (*__once_call)();template<typename _Callable>inline void__once_call_impl(){(*(_Callable*)__once_callable)();}#elseextern function<void()> __once_functor;extern void__set_once_functor_lock_ptr(unique_lock<mutex>*);extern mutex&__get_once_mutex();#endifextern "C" void __once_proxy();/// call_oncetemplate<typename _Callable, typename... _Args>voidcall_once(once_flag& __once, _Callable&& __f, _Args&&... __args){#ifdef _GLIBCXX_HAVE_TLSauto __bound_functor = std::bind<void>(std::forward<_Callable>(__f),std::forward<_Args>(__args)...);__once_callable = &__bound_functor;__once_call = &__once_call_impl<decltype(__bound_functor)>;#elseunique_lock<mutex> __functor_lock(__get_once_mutex());__once_functor = std::bind<void>(std::forward<_Callable>(__f),std::forward<_Args>(__args)...);__set_once_functor_lock_ptr(&__functor_lock);#endifint __e = __gthread_once(&(__once._M_once), &__once_proxy);#ifndef _GLIBCXX_HAVE_TLSif (__functor_lock)__set_once_functor_lock_ptr(0);#endifif (__e)__throw_system_error(__e);}// @} group mutexes_GLIBCXX_END_NAMESPACE_VERSION} // namespace#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1#endif // __GXX_EXPERIMENTAL_CXX0X__#endif // _GLIBCXX_MUTEX